KurtEndress
Well-known member
What is the cost of doing full power acceleration in the i3 in terms of efficiency and battery use?
It’s certainly costly of fuel in an ICE, but there is an argument that it doesn’t make much difference in an EV as they are not nearly as inefficient at high power. I find it hard to believe there is no cost in efficiency, after all BMW put a lead foot symbol on the display if you accelerate too hard. I’ve seen my efficiency figure drop a bit after a quick start.
As a test I just tried resetting my trip computer efficiency figures and did three full throttle 0 to 55 MPH starts over about 1.4 miles. The consumption figure after this was 4.3 mi/kWh, which I found surprisingly good. That means I used 0.33 kW over the 1.4 miles and at most 0.11 kW hour per start. More likely it was less than half of that as at best I might have gotten double the efficiency driving around at low speed.
I really should have done a comparison drive trough the same area at a normal 30 MHP for comparison. I suspect I would have gotten somewhere between 5 and 8 mi/kWh. So there was some cost to the hard acceleration, but was it just due to the momentary aero drag at 55 MPH and the loss from the regen slowing back down?
I suppose you really need a controlled test through the same area comparing slowly accelerating to speed and then with hard acceleration to the same speed. Probably need a nice level stretch of deserted road for that, which can be hard for me to come by. I had to loop around to reuse the same 500 yard/meter stretch of level road.
It’s certainly costly of fuel in an ICE, but there is an argument that it doesn’t make much difference in an EV as they are not nearly as inefficient at high power. I find it hard to believe there is no cost in efficiency, after all BMW put a lead foot symbol on the display if you accelerate too hard. I’ve seen my efficiency figure drop a bit after a quick start.
As a test I just tried resetting my trip computer efficiency figures and did three full throttle 0 to 55 MPH starts over about 1.4 miles. The consumption figure after this was 4.3 mi/kWh, which I found surprisingly good. That means I used 0.33 kW over the 1.4 miles and at most 0.11 kW hour per start. More likely it was less than half of that as at best I might have gotten double the efficiency driving around at low speed.
I really should have done a comparison drive trough the same area at a normal 30 MHP for comparison. I suspect I would have gotten somewhere between 5 and 8 mi/kWh. So there was some cost to the hard acceleration, but was it just due to the momentary aero drag at 55 MPH and the loss from the regen slowing back down?
I suppose you really need a controlled test through the same area comparing slowly accelerating to speed and then with hard acceleration to the same speed. Probably need a nice level stretch of deserted road for that, which can be hard for me to come by. I had to loop around to reuse the same 500 yard/meter stretch of level road.
